The present invention relates generally to turf aerating equipment and relates more particularly to an arrangement for securing hollow turf coring tines to a tine actuating member.
A variety of turf aerating devices have been developed for forming slots or holes in turf to permit the penetration of air, water and nutrients to the grass roots. The type of device which forms holes in the turf commonly utilizes a hollow coring tine as the turf penetrating element. Such tines usually are annular in section and slightly tapered, being larger at their upper ends, to facilitate the discharge of the turf cores therethrough. The mechanism for driving the tines into the ground conventionally provides a reciprocating motion to a group of tines and a given machine normally includes several groups of tines which are driven sequentially into the ground to provide a repeating turf aerating pattern.
Since the tines may strike stones or other impenetrable hard objects hidden within or beneath the turf, they are subject to breakage or deformation. The tines also wear out after an extended period of use. Their manner of attachment must accordingly permit tine replacement when necessary, and should further provide sufficient mounting security to prevent loss of the tines under severe service conditions.
Various arrangements have heretofore been employed for the attachment of turf aerating tines. In one conventional arrangement, the tine upper end is held within a split clamp on the tine carrying member. In another type of attachment, a split collet with external tapered threads is utilized to grip the upper end of the tine. In both of these arrangements, the tines are held in position by a frictional gripping of the substantially cylindrical upper ends of the tines.
Although such tine holding arrangements permit the ready replacement of a tine should it become damaged or unduly worn, they are subject to occasional tine loss due to the loosening of the friction type of clamping mechanism. Such tine loss not only deprives the aerator of its full aerating function, but by leaving metal tines partially protruding from the ground, presents a serious hazard to lawn mowing equipment and especially reel type mowers. It is accordingly important that a tine supporting arrangement be effective in preventing tine loss while still permitting the removal and replacement of individual tines without undue time and effort.
Other tine securing arrangements have been proposed wherein the tines themselves are threaded and/or flanged. Although such tine structures are less prone to tine loss, their use has been limited because of their substantially increased cost.